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245 1 0 _aMetabolic cross talk between cytosolic and plastidial pathways of isoprenoid biosynthesis: unidirectional transport of intermediates across the chloroplast envelope membrane
490 0 _vArchives of BioChemistry and Biophysics, 415(2), p.146-154, 2003
520 3 _aIn higher plants, two independent pathways are responsible for the biosynthesis of isopentenyl diphosphate and dimethylallyl diphosphate, the central five-carbon precursors of all isoprenoids. The cytosolic pathway, which involves mevalonate (MVA)as a key intermediate, provides the precursor molecules for sterols, ubiquinone, and certain sesquiterpenes, whereas the plastidial MVA-independent pathway is involved in the formation of precursors for the biosynthesis of isoprene, monoterpenes, diterpenes, carotenoids, abscisic acid, and the side chains of chlorophylls, tocopherols, and plastoquinone. Recent experiments provided indirect evidence for the presence of an export system for isoprenoid intermediates from the plastids to the cytosol in Arabidopsis thaliana [1]. Here we report that isolated chloroplasts (from spinach, kale, and Indian mustard), envelope membrane vesicles, and proteoliposomes prepared from the solubilized proteins of envelope membranes (from spinach)are capable of the efficient transport of isopentenyl diphosphate and geranyl diphosphate. Lower rates of transport were observed with the substrates farnesyl diphosphate and dimethylallyl diphosphate, whereas geranylgeranyl diphosphate and mevalonate were not transported with appreciable efficiency. Our data suggest that plastid membranes possess a unidirectional proton symport system for the export of specific isoprenoid intermediates involved in the metabolic cross talk between cytosolic and plastidial pathways of isoprenoid biosynthesis.
650 1 4 _aCHLOROPLAST
650 1 4 _a1-DEOXY--XYLULOSE 5-PHOSPHATE
650 1 4 _aISOPENTENYL DIPHOSPHATE
700 1 2 _aBick, J. A.
700 1 2 _aLange, B. M.
700 1 2 _aLange, B. M.
856 4 0 _uhttps://drive.google.com/file/d/1b2G-W-tyCLTg0TWYPVLsYKaQu9GEE1bP/view?usp=drivesdk
_zPara ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx
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